Assembly of elements of a packing-box of corrugated cardboard or similar deformable material



3,306,520 ATED A ALLARD ASSEMBLY OF ELEMENTS OF A PACKING-BOX OF CORRUG CARDBOARD OR SIMILAR DEFORMABLE MATERIAL Y Filed Feb. 9, 1965 Feb. 28, 1967 3,306,520 ASSEMBLY OF ELEMENTS OF A PACKING-BOX F CORRUGATED CARDBOARD OR SIMILAR DEFORMABLE MATERIAL Adrien Allard, Brive-la-Gaillarde, France, assignor to Societe a Rcsponsabilite Limitee: Allard & Fils, Brivela-Gaillarde, France, a corporation of France Filed Feb. 9, 1965, Ser. No. 431,287 Claims priority, application France, Feb. 11, 1964, 963,349, Patent 1,396,369 Claims. (Cl. 229-45) Packing-boxes of corrugated or plain cardboard, or of any other material capable of deformation, such as fruit trays or vegetable cases are generally made from one or a number of blanks which are cut-out, grooved and folded before being assembled. In packings of this kind, the side walls, the bottom or the lid may comprise flaps, turned-down pieces or tongues, co-operating with the adjacent walls so as to ensure the rigidity of the box or case.

In packing-boxes of this kind, it is particularly important that the system of assembly, of locking and/or closure of the various constituent elements ensures a perfect interlock in the assembled position, in order to prevent any untimely separation of the elements.

An object of the present invention is to provide a system of assembly which complies with these fundamental necessities.

In principle, the invention contemplates providing one of the two elements which it is desired to assemble to gether with shoulders comprising at least one lug, similar to a latch, and arranging in the other element a housing for this latch, similar to a keeper or staple, which is provided with an abutment against which the shoulder or shoulders become blocked so as to ensure hooking together of the two elements. The latch and the staple are respectively cut-out from the mass of the two ele ments to be associated, the staple being formed in a portion constituted by at least two superimposed thicknesses. The latch is longer than the external cut-out contour of the staple, and can only be introduced into this latter by bending. It then reassumes its initial shape by the elasticity of the semi-rigid material of which it is formed so as to become interposed between the two thicknesses of the part of the element in which the staple is formed, its lug or lugs becoming blocked against the stop provided for that purpose in the staple. The lugs are thus hooked under this stop since the latch is interposed between two thicknesses and the two elements are in consequence locked in their assembled position. I

It is possible, for example, to hook and lock together easily in this manner the side walls of a packing-box to each other and/ or to the bottom and the lid of the packing-box, the latter thus having great safety in use during the course of operations of stowing and handling.

The invention will be described below, by way of example, and without any limitation, in its application to the closure of a box with a turn-back cover. In the description, reference will be made to the accompanying drawings, in which:

FIG. 1 is a view in perspective of an open case, the lid of which can be booked and locked according to the invention, on the transverse walls.

FIG. 2 shows a shoulder or latch housed in a recess or staple comprising a cut-out disengagement portion.

FIGS. 3, 4 and 5 show in perspective different forms of construction of the housings of the latch.

The corrugated cardboard box 1 illustrated in FIG. 1 comprises a lid 2, articulated by a line of folding 3 on one of its longitudinal walls 4. The transverse Walls 5 nited States Patent 0 3,306,520- Patented Feb. 28, 1967 are reinforced by an internal flap 6 articulated by a line of folding 7 on the wall 5.

In accordance with the invention, the lid 1 is provided on each of its lateral edges with two shoulders or latches, of which one, 8, comprises a simple lug and the other,

9, comprises two lugs. These latches are given the profile illustrated in FIG. 1 which are comparable to the profile of a marine anchor. Each of the shoulders is engaged respectively in a housing or staple 10, 11, formed in the walls 5, and in a slot 12, 13, formed in the line of fold or the strip '7 forming the edge of the wall 5.

Each of the staples comprises one or a number of abutments for the lug or lugs of the corresponding latch, namely an abutment 14 for the staple 10 and two abutments 15 and 15a for the staple 11.

In order to close the lid, the lugs of the latches are brought opposite their respective staple, and they are slightly deformed by bending the cardboard or semi-rigid material of which they are formed, so as to introduce them into their housings. The latches are pushed to cause them to pass fully home into their housings, in which they become engaged by resuming their initial shape by elasticity, while at the same time the lugs are applied against the abutments of the staples so as to ensure a hooking engagement.

Conversely, in order to extract the shoulder from the staple, it is only necessary to apply a slight pressure on the one hand on the latch towards the exterior of the box and on the other hand on the walls of the corresponding staple towards the inside of the box so as to apply opposite deformations to these elements and to prepare the disengagement of the latch.

The engagement of the latch in its staple, like its extraction, thus requires that the material of which they are made can be deformed momentarily by bending while at the same time possessing a relative elasticity which enables it to return to its initial condition.

FIGS. 2, 3, 4 and 5 illustrate alternative forms of construction of latches and staples according to the invention.

In the type illustrated in FIG. 2, the profile of the external cut-out contour of the staple is such that the latch 8a is largely covered by the walls of the packing box, that is to say it is deeply engaged between the walls 5a and 6a of the staple. In this way, all risk of accidental release of the latch, resulting from an accidental widening of the staple during handling is avoided. How ever, in order to further facilitate the extraction of the latch from its housing, an additional notch 16 is cut in the outer wall 5a, so as to enable a finger or any similar part to be introduced in order to disengage the lug.

In the alternative form shown in FIG. 3, the latch 8b and the staple 10b have identical profiles. The wall in which the staple is formed comprises a triple thickness 5b, 6b and 17, in order to reinforce the packing-box. The staple is cut-out in the outer thickness 5b and in the intermediate thickness 17, which enables the latch to be introduced more deeply into its housing so as to reduce thereby the risk of accidental disengagement. The abutment 14b of the staple is constituted by the upper cut-out contour of the intermediate thickness 17, which enables the latch and the staple to be perfectly fixed in the engaged position, well above the strip 71) which constitutes the edge of the wall.

In the alternative forms shown in FIGS. 4 and 5, the latches 8c and 8d with double lugs are engaged in the staples, not through a cut made in the outer wall 50 or 5d, but through a cut-13a in the case of FIG. 4-formed in the strip 70 or 7d which forms the edge of the wall. This out has the profile of a trapezium, the large base of which has substantially the same dimension as the large transverse dimension of the latch at the level of the lugs, so as to enable them to be introduced easily, the small base of the trapezium being substantially equal to the length of the body of the latch for which it serves as a slide. After having been introduced into the cut on the side of the large base of the trapezium, the latch is applied by its elasticity against the outer wall 5c or 511, and the abutment of the staple is thus constituted by the strip 70 or 7d of the edge.

In order to prevent the lugs from being located level with the larger base of the cut, as a result of play of the latch inside its staple, the consequence of which they would be liable to become disengaged, there may be provided a flap 19 (FIG. 5), articulated on the inside wall 6b level with the large base of the cut, of which it has the same profile. When introducing the latch into the staple, this flap 19 is pushed back between the walls 5d and 6d. In this position, it acts as a spring and is supported against the latch 8d which it pushes back against the outer Wall 5d, so as to hold the lugs on the strip 7d.

It will be noted that in the type illustrated in FIG. 4, the outer cut 100 of the staple is visible, while in the alternative form shown in FIG. 5, the outer wall 5d has no cut.

In order to facilitate introduction of the latch into the cut formed in the strip which constitutes the edge of the wall, it will be an advantage to extend the large base of this cut by slots 20, as shown in FIG. 5.

In the alternative forms illustrated in FIGS. 4 and 5, no breaking-open of the packing-box can practically be effected without leaving visible traces which indicate damage to the lugs and the abutments of the staples, and particularly of the strips forming the edges.

Although the invention has been described in the form of a coupling between the lid and the walls of a packingbox, it is clear that it can be applied to the assembly of any elements of a packing-case, or more generally to the assembly of the various elements of a single unit or a number of units.

What I claim is:

1. A system of assembly of two elements of a packingboX of semi-rigid material capable of deformation, wherein one of the elements comprises at least one shoulder provided with at least one lug, the said shoulder being adapted to act as a latch and being introduced into a housing formed between two superimposed thicknesses of the other element, the said housing comprising, between the said two thicknesses, an abutment for each lug of the latch so as to serve as a staple, and being provided with an opening, the dimensions of which are such that the introduction of the latch into the housing through the said opening can only be effected after having deformed the latch so as to bend it, the latch then resuming its initial shape by elasticity between the two thicknesses delimiting the staple in which it is thus locked, said window through which the latch is introduced being formed in one of the two thicknesses of the element which carries the staple.

2. A system of assembly of two elements in accordance with claim 1, in which the said two thicknesses are joined together by a strip provided with a cut for the passage of the body of the latch, the abutments for the lugs being constituted by the parts of the said strip which are contiguous to the cut-out contour.

3. A system of assembly of two elements of a packing-box of semi-rigid material capable of deformation, wherein one of the elements comprises at least one shoulder having at least one lug, the other element comprising two superimposed thicknesses coupled together by a flat strip defining a space between the thicknesses for housing the shoulder, said flat strip having an opening therein in the form of a trapezium having a large base of sufficient length to receive the shoulder and a small base of a length less than that of the shoulder for securing the shoulder by abutment of the lug thereof against the flat strip in the region of the small base, and a flap having an outline corresponding to the trapezium opening and foldably connected to one of the two thicknesses at the level of the large base of said opening, said flap being pushed back between the two thicknesses when the shoulder is introduced into the opening and acting in turn to push the shoulder by elasticity against the other of the thicknesses in order to lock the lug in abutment beneath the fiat strip.

4. A system of assembly of two elements of a packing-box of semi-rigid material capable of deformation, wherein one of the elements comprises at least one shoulder provided with at least one lug, the said shoulder being adapted to act as a latch and being introduced into a housing formed between two superimposed thicknesses of the other element, the said housing comprising, between the said two thicknesses, an abutment for each lug of the latch so as to serve as a staple, and being provided with an opening, the dimensions of which are such that the introduction of the latch into the housing through the said opening can only be effected after having deformed the latch so as to bend it, the latch then resuming its initial shape by elasticity between the two thicknesses delimiting the staple in which it is thus locked, and a third thickness interposed between the said two thicknesses, said third thickness being provided with a cut-out portion which receives the latch and has substantially the same form as the said latch.

5. A system as claimed in claim 1 wherein the length of the shoulder in the direction of introduction into the housing is greater than the extent of said opening through which the shoulder is introduced.

References Cited by the Examiner UNITED STATES PATENTS 1,156,444 10/1915 Stevens 22923 2,190,433 2/1940 Palmer 22936 X 2,614,746 10/ 1952 Frankenstein.

2,619,276 11/ 1952 Gibbons.

2,678,153 5/1954 Buttery 22936 3,019,958 2/1962 Asman et al. 22936 X 3,029,996 4/1962 Drummond 22936 GEORGE O. RALSTQN, Primary Examiner, 

1. A SYSTEM OF ASSEMBLY OF TWO ELEMENTS OF A PACKINGBOX OF SEMI-RIGID MATERIAL CAPABLE OF DEFORMATION, WHEREIN ONE OF THE ELEMENTS COMPRISES AT LEAST ONE SHOULDER PROVIDED WITH AT LEAST ONE LUG, THE SAID SHOULDER BEING ADAPTED TO ACT AS A LATCH AND BEING INTRODUCED INTO A HOUSING FORMED BETWEEN TWO SUPERIMPOSED THICKNESSES OF THE OTHER ELEMENT, THE SAID HOUSING COMPRISING, BETWEEN THE SAID TWO THICKNESSES, AN ABUTMENT FOR EACH LUG OF THE LATCH SO AS TO SERVE AS A STAPLE, AND BEING PROVIDED WITH AN OPENING, THE DIMENSIONS OF WHICH ARE SUCH THAT THE INTRODUCTION OF THE LATCH INTO THE HOUSING THROUGH THE SAID OPENING CAN ONLY BE EFFECTED AFTER HAVING DEFORMED THE LATCH SO AS TO BEND IT, THE LATCH THEN RESUMING ITS INITIAL SHAPE BY ELASTICITY BETWEEN THE TWO THICKNESSES DELIMITING THE STAPLE IN WHICH IT IS THUS LOCKED, SAID WINDOW THROUGH WHICH THE LATCH IS INTRODUCED BEING FORMED IN ONE OF THE TWO THICKNESSES OF THE ELEMENT WHICH CARRIES THE STAPLE. 